1. Field of the Invention
The present invention relates to a device and a method for testing SAS channels. More particularly, the present invention relates to a bridge device for testing SAS channels by using a PCI-E channel and a testing method thereof.
2. Related Art
Serial attached SCSI (SAS) interface is a new generation of small computer small interface (SCSI interface). SAS is a novel interface developed following the parallel SCSI interface. Therefore, the SAS interface can provide the function of multi-interface connection and the data can be transmitted bi-directionally at a rate of 6 Gb/s. Additionally, through the design of reducing the connection wire, the SAS interface has the advantage of reducing the inner space of the system, and the SAS interface is also backward compatible, for example, SATA (Serial ATA) hard disks.
SAS channels utilizes low voltage difference signals (LVDS) for data transmission, and each pair of difference lines has TX+, TX−, RX+, and RX− respectively according to the criterion of SAS. On each pair of difference lines, the data transmission speed of 1.5 Gbps and 3.0 Gbps can be utilized. The transmission voltage (TX) and the receiving voltage (RX) used by the SAS channels are 800-1600 mV and 275-1600 mV respectively.
Referring to FIG. 1a, it is a schematic view of a conventional connection between a server and SAS hard disks. A conventional process for testing SAS channels includes, connecting a control terminal 110 to an SAS hard disks 130 through an SAS back plate 120; performing an accessing operation to the SAS hard disks 130 by a detection program; and finally, detecting whether the SAS channels can access normally by means of reading from and writing to the SAS hard disks 130. The SAS back plate 120 respectively has a plurality of pairs of SAS interfaces 121 thereon, for respectively connecting the SAS hard disks 130 to the SAS interfaces 121. Referring to FIG. 1b, it is a flow chart of the detection of conventional SAS channels. First of all, the SAS hard disks under test are installed on the SAS back plate (S110). Next, the testing programs of the system are activated (S120). Then, the testing programs perform an accessing operation to the SAS hard disks (S130). Finally, the system under test receives a test report about the accessing operation of the SAS hard disks (S140).
However, as the SAS back plate 120 has 8-16 SAS interfaces 121 therein, and in Step S110, the SAS back plate 120 and the SAS hard disks 130 must be replaced through manual operation, it is quite time-consuming when disassembling/assembling the equivalent number of SAS hard disks 130. Additionally, when rebooting the system, additional time is needed. In this way, the overall testing time is prolonged, and thus the testing efficiency is lowered.